Add solution configuration and tooling

- .gitignore for .NET/Blazor project
- VS Code launch and task configurations
- Solution file (Duempelkas.slnx)
- NuGet configuration

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": ".NET Core Launch (Desktop)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            "program": "${workspaceFolder}/src/Duempelkas.Desktop/bin/Debug/net10.0/Duempelkas.Desktop.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}/src/Duempelkas.Desktop",
+            "stopAtEntry": false,
+            "console": "internalConsole"
+        }
+    ]
+}